UIImageView+AFNetworking.m

// UIImageView+AFNetworking.m
// Copyright (c) 2011–2016 Alamofire Software Foundation ( http://alamofire.org/ )
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

#import "UIImageView+AFNetworking.h"

#import <objc/runtime.h>

#if TARGET_OS_IOS || TARGET_OS_TV

#import "AFImageDownloader.h"
#import "NSString+MD5.h"

@interface UIImageView (_AFNetworking)
@property (readwrite, nonatomic, strong, setter=af_setActiveImageDownloadReceipt:) AFImageDownloadReceipt* af_activeImageDownloadReceipt;
@end

@implementation UIImageView (_AFNetworking)

- (AFImageDownloadReceipt*)af_activeImageDownloadReceipt
{
    return (AFImageDownloadReceipt*)objc_getAssociatedObject (self, @selector (af_activeImageDownloadReceipt));
}

- (void)af_setActiveImageDownloadReceipt:(AFImageDownloadReceipt*)imageDownloadReceipt
{
    objc_setAssociatedObject (self, @selector (af_activeImageDownloadReceipt), imageDownloadReceipt, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}

@end

#pragma mark -

@implementation UIImageView (AFNetworking)

+ (AFImageDownloader*)sharedImageDownloader
{
    return objc_getAssociatedObject (self, @selector (sharedImageDownloader)) ?: [AFImageDownloader defaultInstance];
}

+ (void)setSharedImageDownloader:(AFImageDownloader*)imageDownloader
{
    objc_setAssociatedObject (self, @selector (sharedImageDownloader), imageDownloader, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}

#pragma mark -

- (void)setImageWithURL:(NSURL*)url
{
    [self setImageWithURL:url placeholderImage:nil];
}

- (void)setImageWithURL:(NSURL*)url placeholderImage:(UIImage*)placeholderImage
{
    NSMutableURLRequest* request = [NSMutableURLRequest requestWithURL:url];
    [request addValue:@"image/*" forHTTPHeaderField:@"Accept"];

    [self setImageWithURLRequest:request placeholderImage:placeholderImage success:nil failure:nil];
}

- (void)setImageWithURLRequest:(NSURLRequest*)urlRequest
              placeholderImage:(UIImage*)placeholderImage
                       success:(void (^) (NSURLRequest* request, NSHTTPURLResponse* _Nullable response, UIImage* image))success
                       failure:(void (^) (NSURLRequest* request, NSHTTPURLResponse* _Nullable response, NSError* error))failure
{

    if ([urlRequest URL] == nil)
    {
        [self cancelImageDownloadTask];
        self.image = placeholderImage;
        return;
    }

    if ([self isActiveTaskURLEqualToURLRequest:urlRequest])
    {
        return;
    }

    [self cancelImageDownloadTask];

    AFImageDownloader* downloader = [[self class] sharedImageDownloader];
    id<AFImageRequestCache> imageCache = downloader.imageCache;

    // Use the image from the image cache if it exists
    UIImage* cachedImage = [imageCache imageforRequest:urlRequest withAdditionalIdentifier:nil];
    if (cachedImage)
    {
        if (success)
        {
            success (urlRequest, nil, cachedImage);
        }
        else
        {
            self.image = cachedImage;
        }
        [self clearActiveDownloadInformation];
    }
    else
    {
        if (placeholderImage)
        {
            self.image = placeholderImage;
        }

        __weak __typeof(self) weakSelf = self;
        NSUUID* downloadID = [NSUUID UUID];
        AFImageDownloadReceipt* receipt;
        receipt = [downloader downloadImageForURLRequest:urlRequest
        withReceiptID:downloadID
        success:^(NSURLRequest* _Nonnull request, NSHTTPURLResponse* _Nullable response, UIImage* _Nonnull responseObject) {
          __strong __typeof(weakSelf) strongSelf = weakSelf;
          if ([strongSelf.af_activeImageDownloadReceipt.receiptID isEqual:downloadID])
          {
              if (success)
              {
                  success (request, response, responseObject);
              }
              else if (responseObject)
              {
                  strongSelf.image = responseObject;
              }
              [strongSelf clearActiveDownloadInformation];
          }

        }
        failure:^(NSURLRequest* _Nonnull request, NSHTTPURLResponse* _Nullable response, NSError* _Nonnull error) {
          __strong __typeof(weakSelf) strongSelf = weakSelf;
          if ([strongSelf.af_activeImageDownloadReceipt.receiptID isEqual:downloadID])
          {
              if (failure)
              {
                  failure (request, response, error);
              }
              [strongSelf clearActiveDownloadInformation];
          }
        }];

        self.af_activeImageDownloadReceipt = receipt;
    }
}

- (void)cancelImageDownloadTask
{
    if (self.af_activeImageDownloadReceipt != nil)
    {
        [[self.class sharedImageDownloader] cancelTaskForImageDownloadReceipt:self.af_activeImageDownloadReceipt];
        [self clearActiveDownloadInformation];
    }
}

- (void)clearActiveDownloadInformation
{
    self.af_activeImageDownloadReceipt = nil;
}

- (BOOL)isActiveTaskURLEqualToURLRequest:(NSURLRequest*)urlRequest
{
    return [self.af_activeImageDownloadReceipt.task.originalRequest.URL.absoluteString isEqualToString:urlRequest.URL.absoluteString];
}

@end

#endif